Debt (Senior Credit Facilities Narrative) (Details) - USD ($) $ in Millions			12 Months Ended
		Jul. 15, 2016	Dec. 31, 2016
Senior Unsecured Term Loan Due 2021 [Member]
Debt Instrument [Line Items]
Secured Debt	[1]	$ 500
Revolving Credit Facility [Member] | Senior Unsecured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		1,000
Proceeds from Lines of Credit		$ 409	$ 409

[1] The margin for borrowings under the senior unsecured term loan due 2021 was 1.5% above LIBOR at current Celanese credit ratings.